Process for the production of pure white discharging effects on cellulosic materials



Patented Aug. 17, 1948 PROCESS FOR THE PRODUCTION OF PURE WHITE DISCHARGING EFFECTS ON CEL- LULOSIC MATERIALS Charles Babey, Basel, Switzerland, and Frederic Leathley Goodall, Burley-in-Wharfedale, England, assignors to J. R. Geigy A.-G., Basel,

Switzerland No Drawing. Application September 27, 1946, Se-

rial No. 699,632. In Switzerland September 26,

Section 1, Public Law 690, August 8, 1946 7 Claims.

It is a known fact that dyeings resulting from copper-containing or aiter-coppered dyestuffs can be white discharged only with difliculties and in an unsatisfactory manner for practical purposes, even if said dyestufis are derived from azo dyestufis discharging in a pure white, when used in a metal-free condition. Particularly for the discharge printing on artificial silk only brownish to olive shades are obtained which do not satisfy the requirements of practice, As dyeings resulting from copper-containing or after-coppered dyestuffs are distinguished by very good light-fastness properties and often also by very good fastness properties in the moist state, a disis diminished. Fixation agents, partly in combination with copper compounds, have already become known in the trade. When for instance cellulosic dyeings of dischargeable dyestuffs are made water-fast by means of the said coppercontaining fixation agents, there sometimes arises the difiiculty, and this particularly for dyeings on viscose rayon, that unobjectionable white discharges can no longer be produced with the usual discharge printing pastes containing hydrosulfite.

When, in order to avoid the said disadvantage, such dyeings are discharged on Viscose rayon before the treatment thereof with the copper-containing fixation agent by means of a known and charging method rendering possible the use of usual hydrosulfite containing discharge printing the said dyestuff class is particularly valuable. paste t k place and h th materials are With respect thereto it may be noted that a treated only subsequently with the [copper-conmethod for discharging dyeings with copper-con" taining fixation agent in order to thus avoid the taittmg dyestuffs h already become k w said disadvantage, nevertheless no :white shades Whlctt method consltts m that redP-ctlon are produced, but only brownish discharge figures chargmg with alkahne hydrosulfite 15 followed will result which are absolutely unsatisfactory for by an oxidation treatment of only the discharge practical purposes area by means of hydrogen petoxlde' In vlew We have now found that dyeings resulting from of Propertles 0t t copper-containing dyestufis which derive from peroxide this method requlr es extreme caution in azo dyestuffs being dischargeable in the metal order to only bring the d1scharged Places Into free condition can be discharged by means of j t mm the oxldaitlon agent not h hydrosulfite, while producing pure white areas, to hich per se is complicated for the re son that discharge paste Moreove? t also possible it necessitates two according to the present invention, to produce Furthermore it is known to improve the fastcompletely Wmte.d1scharges of mettal'contamnlg ness propertiesbf dyeings in their moist state by or metal-free dyeltlgfs of dyestuffs dlschargeable.m subjecting the dyed material to an after-treatmetal-free tcqndltlon Whose fastness propgrtlts ment with solutions of interaction products of low and partlcularly the ,fastness propertles m aliphatic aldehydes and compounds containing the molst state have Improved t n of amino or inn-n0 groups, which interaction prom the commonly used fixation agents wlth additlon ucts are resinous per se or convertible into 0t coppet Salts; w workltlg accordmg to the resinous compounds For this purpose for present lnvention, 1t is of no importance whether ample interaction products of formaldehyde and 40 dyestufis resulting in a complex hnkag? Wlth urea, thiourea, cyanamide, dicyanodiamide, per or dyestufis of non-metallisable kind are to amine and the like as well as mixtures or interbe treated- This is the more surprising as the action products of mixtures respectively of the fixation effect most. probably depends on t said or similar compounds it formaldehyde formation of water-insoluble, resinous covering have been recommended. It is true that by such layers on the treated and dy material, Which a treatment the fastness properties of the dyeings layers Could be capable of pr v g the p in in the moist state will be improved, but, on the of the discharge paste and 0f the Oyano -y ldother hand, this method shows the disadvantage g agent therethloughthat the lightfastness of the dyeings is consider- By the expression agents yielding cyano ions ably decreased. Such disadvantage may be remay be understood generally such compounds moved by adding soluble copper salts containing which, during the discharging process or steamionogenous or complex bound copper, such as ing process yield sufiicient cyano ions to remove copper acetate, to the after treatment baths, the metal resulting from the copper-containing whereby the influence of the fixation agent condy s Such agents may particularly be sisting in decreasing the light-fastness properties mentioned:

1. The soluble salts of hydrocyanic acid, like sodium cyanide, potassium cyanide and so on,

2. The insoluble salts of hydrocyanic acid, such as zinc cyanide, cadmium cyanide and the like, which either by hydrolysis or by chemical interaction, for instance with alkali carbonates, produce cyano ions during the discharging or steaming operation,

3. The complex salts of hydrocyanic acid, whose metallic central atom may be removed by copper, such as sodium zinc cyanide, potassium zinc cyanide, the solution of zinc cyanide in aqueous ammonia, sodium or potassium cadmium cyanide and so forth, and

4. Other methods giving cyano ions, such as the decomposition of cyanohydrines, e. g. formaldehyde cyanohydrine etc., which decomposition takes place under the existing conditions of the discharging and steaming method.

The addition of the agents yielding cyano ions to the discharge paste constitutes the most simple and preferred method. Of course, it is also possible, after the usual hydrosulfite discharging, to treat the discharged areas with agents yielding cyano ions.

By the expressions cellulosic dyeing of dischargeable dyestuffs treated with copper-containing fixation agents or cellulosic materials dyed with dischargeable dyestuffs and treated with copper-containing agents respectively used in the present specification and claims may be understood materials which are dyed with dyestuffs dischargeable in a metal-free condition. If such dyestuiTs are metallisable, the expression agents containing copper means a copper salt which contains ionogenous or complex bound copper, or a copper-containing fastness improving agent. Should these dyestufis not be metallisable, then the agent containing copper may be a copper salt containing ionogenous or complex bound cop per and being used for instance in combination with a fastness improving agent, or also a copper containing fastness improving agent.

The present invention will now be illustrated by the following examples, without being limited thereto. The parts are by weight, unless otherwise stated.

Example 1 A blue .after-coppered dyeing on artificial silk, produced with the dyestufi of Example 1 of Swiss Patent No. 236,584

[4,4-dia1(1i1ino-3,3 dimethoxy-diphenyl 3 (Z-aminobcnzoic uci acid 2-amino-5-hydroxy-naphthalene-7-su1fo11ic acidh] is printed by roller printing with a neutral hydrosulfite discharge paste prepared as follows:

Parts Industrial gum 1:1 400 Mixture of formaldehyde sodium sulfoxylate and zinc oxide 250 Sodium zine cyanide 25 Water 325 Example 2 A black, after-coppered dyeing on viscose rayon produced with the dyestuff of Example 2 of Swiss patent application Ser. No. 80,265

[cf. Swiss Patent No. 250,813; m-crcsotinic acid 4,4- dlamino-llg-dimethoxydiphenyl (5nitro-2-aminobcnzoic ac: acid 2-amino-5-hydroxynaphthalcnc-7-su][onic acid)] is printed by roller printing with an alkaline hydrosulfite discharge paste prepared as follows:

Parts Starch tragacanth thickening 400 Mixture of V5 formaldehyde sodium sulfoxylate and zinc oxide 150 Formaldehyde sodium ulfoxylate Potash 50 Zinc cyanide 25 Concentrated ammonia water 25 Water 250 Then it is steamed and further treated in the usual manner. Thus a pure white discharge design is produced on the black dyeing, whereas without addition of zinc cyanide only an olive brown discharge ground will result. Similar results are obtained when using, instead of zinc cyanide, corresponding quantities of the agents yielding cyano ions and mentioned sub 1 to 3 in the foregoing specification.

Example 3 A brown, copper-containing dyeing on artificial silk produced with the trisazo dyestufi disclosed in French Patent No. 858,095, Example 1 thereof [salicylic acid benzidinc (2-amino-1-hydroxy benzenc-4-sulfamidc resorcinoD] is printed with a hydrosulfite discharge paste prepared as described in the above Example 2; then further procedure is in the usual way. Thus a pure white discharge design is produced on the brown dyeing, whereas Without addition of zinc cyanide to the discharge paste only an orange brown discharge ground will result.

Example 4 A green-blue dyeing on artificial silk, produced with the after-coppere'd dyestufi called Diphenyl Brilliant Blue FF (Schultz, Farbstofftabellen, 7th edition, No. 510) is printed with a hydrosulfite discharge paste prepared in the manner indicated in the above Example 2. After a usual workin up a pure White discharge design is produced on the green-blue dyeing, while without addition of zinc cyanide to the discharge paste only a valueless brownish discharge ground is obtained.

Example 5 A black, after-coppered dyeing on viscose rayon, produced with the dyestuff of Example 2 of Swiss patent application Ser. No. 80,265 (see Example 2, supra), is printed by roller printing with an alkaline hydrosulfite discharge paste of the following composition:

Parts Starch-.tragacanth thickening 400 Mixture of formaldehyde sodium sulfoxylate and zinc oxide Formaldehyde sodium sulfoxylate 100 Potash 50 Formaldehyde cyanohydrine 30 Concentrated ammonia water 20 Water 250 Then the material is steamed and further worked in the usual manner. Thus a pure, white discharge design is obtained on the black dyeing, whereas without addition of formaldehyde cyanohydrine to the discharge paste only an olive brown discharge ground is produced.

Example 6 The dyeing used in the above Example 1 is printed with an alkaline hydrosulfite discharge paste of the following composition:

Parts Industrial gum 1:.1 400 Mixture of formaldehyde sodium sulfoxylate and /5 zinc oxide 150 Formaldehyde sodium sulfoxylate 100 Potash 50 Benzaldehyde sulfonic acid cyanohydrine (obtainable from benzaldehyde-B-sulfonic acid with hydrocyanic acid) 30 Concentrated ammonia water 20 Water 250 Then the goods are steamed and further worked in the usual manner. Thus, on .the blue dyeing, a pure white discharge design is produced, whereas without addition of benzaldehyde sulfonic acid cyanohydrine only a brownish discharge ground will be obtained.

Example 7 A blue dyeing on viscose rayon, produced with the dyestuff of Example 1 of Swiss Patent No.

236,584 (see Example 1, supra) and after-treated with a copper-containing fixation agent, as well as with copper acetate, is printed 'by roller printing with a neutral hydrosulfite discharge paste prepared as follows:

Concentrated ammonia water 25 Water 250 The material is steamed and further processed in the usual manner. Thus sharp white discharge figures are obtained, whereas a design treated in exactly the same manner with a discharge paste containing no zinc cyanide will only produce unsharp spotted brownish discharge figures.

Example 8 A green-blue dyeing on viscose rayon, produced with the dyestuff called Diphenyl Brilliant Blue FF (Schultz, Farbstofita'bellen, 7th edition, No. 510) and after-treated with a copper-containing fixation agent, is printed with the hydrosulfite discharge paste described in the above Example 7. After the usual Working up a pure white discharge design is produced on the green-blue dyeing, whereas the same hydrosulfite discharge paste without zinc cyanide is only incompletely efiicacious and produces spotted designs.

If, instead of the above dyeing, a dyeing produced with the dyestuff of Example 1 of Swiss Patent No. 236,584 (see Example 1, supra) and after-treated with a copper-containing fixation agent is used, the discharge paste described in the above Example '7 yields beautiful white dis- 6. charge figures, while in the absence of zinc cyanide the same discharge paste is not capable of producing White discharge areas.

Example 9 A green dyeing produced viscose rayon with the dyestuff of Swiss Patent No. 153,709

lmetanilic acid 1-naphthylamine-7-sulionic acid lailgino-xnaphtholmethylether-dsulfonic acid (anilin 2, 5-aminonaphthol-7-sulfonic acid)] and made fast to washing by means of a copper-containing fixation agent, is printed byroller printing with the hydrosulfite discharge .paste described in the above Example 7, then steamed and thoroughly rinsed. Thus white to slightly yellowish discharge figures are obtained, whereas the same discharge paste containing no zinc cyanide produces only brown-violet discharge grounds.

Ea'ample 10 A violet viscose rayon dyeing, made with'the diazo dyestufi resulting from a p-aminobenzene sulfonic acid as star-ting component, 1-amino-2- methoxy-5-methylbenzene as middle component and 2-phenylamino-5-hydroxynaphthalene-7- sulfonic acid as final component, which dyeing has been made fast to washing by treating it with a copper-containing fixation agent, is printed with the hydrosulfite discharge paste described in the above Example 7, then steamed and rinsed. Thus pure white discharge figures will be produced, whereas the same discharge paste containing no zinc cyanide give only grey discharge grounds.

The following table shows some further examples, (a) being the discharge ground of the dyeing when using a hydrosulfite discharge paste like that described in Example 1, and (b) being the discharge ground of the dyeing when using a hydrosulfit'e discharge paste in the absence of zinc cyanide.

Metanilic acid l-naphthylamine-7-sulfonic acid aminohydroquinone-dimcthylether (metanilic acid 3&1 2,fi aminonaphtholfl sulfonic acid).

Of course, any other cyanide compound can be substituted for zinc cyanide in the above examples.

What we claim is:

1. A process for the production of pure white discharging effects on cellulosic materials dyed with dischargeable dyestuffs and treated with copper-containing agent which comprises applying to the materials a discharge composition containing a thickening agent as well as a sulfoxylate formaldehyde compound and treating the discharged areas of the materials with an agent yielding cyano ions.

2. A process for the production of pure white discharging effects on cellulosic materials dyed with dischargeable dyestuffs and treated with copper-containing agents, which comprises applying to the materials a discharge composition containing a thickening agent, a sulfoxylate formaldehyde compound and an agent yielding cyano ions.

3. A process for the production of pure white discharging efiects on cellulosic material dyed with dischargea'ble dyestuffs and treated with cop'- per-containing agents, which comprises applying to the materials a discharge composition containing a thickening agent, a sulfoxylate formaldehyde compound and a salt of the hydrocyam'c acid yielding cyano ions.

4. A process for the production of pure white discharging effects on cellulosic materials dyed with disch argeable dyestufis and treated with copper-containing agents, which comprises applying to the materials a discharge composition containing a thickening agent, a sulfoxylate formaldehyde compound and an alkali cyanide.

5. A process for the production of pure white discharging effects on cellulosic materials dyed with dischargeable dyestuffs and treated with copper-containing agents, which comprises applying to the materials a discharge composition containing a thickening agent, a sulfoxylate formaldehyde compound and sodium cyanide.

6. A process for the production of pure White discharging efiects on cellulosic materials dyed with dischargeable dyestuffs and treated with copper-containing agents, which comprises applying to the materials a discharge composition containing a thickening agent, a sulfoXylate formaldehyde compound and zinc-cyanide in ammonia.

7. A process for the production of pure white discharging effects on cellulosic materials dyed with dischargeahle dyestuffs and treated with copper-containing agents, which comprises applying .to the materials a discharge composition containing a thickening agent, a sulfoxylate formaldehyde compound and the water-soluble sodium zinc cyanide.

CHARLES BABEY. FREDERIC LEATHLEY GOODALL. 

